NSC DM74LS161A Synchronous 4-bit binary counter Datasheet

54LS161A/DM54LS161A/DM74LS161A,
54LS163A/DM54LS163A/DM74LS163A
Synchronous 4-Bit Binary Counters
General Description
These synchronous, presettable counters feature an internal carry look-ahead for application in high-speed counting
designs. The LS161A and LS163A are 4-bit binary counters.
The carry output is decoded by means of a NOR gate, thus
preventing spikes during the normal counting mode of operation. Synchronous operation is provided by having all flipflops clocked simultaneously so that the outputs change coincident with each other when so instructed by the countenable inputs and internal gating. This mode of operation
eliminates the output counting spikes which are normally
associated with asynchronous (ripple clock) counters. A
buffered clock input triggers the four flip-flops on the rising
(positive-going) edge of the clock input waveform.
These counters are fully programmable; that is, the outputs
may be preset to either level. As presetting is synchronous,
setting up a low level at the load input disables the counter
and causes the outputs to agree with the setup data after
the next clock pulse, regardless of the levels of the enable
input. The clear function for the LS161A is asynchronous;
and a low level at the clear input sets all four of the flip-flop
outputs low, regardless of the levels of clock, load, or enable inputs. The clear function for the LS163A is synchronous; and a low level at the clear inputs sets all four of the
flip-flop outputs low after the next clock pulse, regardless of
the levels of the enable inputs. This synchronous clear allows the count length to be modified easily, as decoding the
maximum count desired can be accomplished with one external NAND gate. The gate output is connected to the clear
input to synchronously clear the counter to all low outputs.
The carry look-ahead circuitry provides for cascading counters for n-bit synchronous applications without additional
gating. Instrumental in accomplishing this function are two
count-enable inputs and a ripple carry output.
Both count-enable inputs (P and T) must be high to count,
and input T is fed forward to enable the ripple carry output.
The ripple carry output thus enabled will produce a high-level output pulse with a duration approximately equal to the
high-level portion of the QA output. This high-level overflow
ripple carry pulse can be used to enable successive cascaded stages. High-to-low level transitions at the enable P or T
inputs may occur, regardless of the logic level of the clock.
These counters feature a fully independent clock circuit.
Changes made to control inputs (enable P or T or load) that
will modify the operating mode have no effect until clocking
occurs. The function of the counter (whether enabled, disabled, loading, or counting) will be dictated solely by the
conditions meeting the stable set-up and hold times.
Features
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Synchronously programmable
Internal look-ahead for fast counting
Carry output for n-bit cascading
Synchronous counting
Load control line
Diode-clamped inputs
Typical propagation time, clock to Q output 14 ns
Typical clock frequency 32 MHz
Typical power dissipation 93 mW
Alternate
Military/Aerospace
device
(54LS161,
54LS163) is available. Contact a National Semiconductor Sales Office/Distributor for specificaitons.
Connection Diagram
Dual-In-Line Package
Order Numbers 54LS161ADMQB, 54LS161AFMQB,
54LS161ALMQB, 54LS163ADMQB, 54LS163AFMQB,
54LS163ALMQB, DM54LS161AJ, DM54LS161AW,
DM54LS163AJ, DM54LS163AW, DM74LS161AM,
DM74LS161AN, DM74LS163AM or DM74LS163AN
See NS Package Number E20A, J16A,
M16A, N16E or W16A
TL/F/6397 – 1
C1995 National Semiconductor Corporation
TL/F/6397
RRD-B30M105/Printed in U. S. A.
54LS161A/DM54LS161A/DM74LS161A, 54LS163A/DM54LS163A/DM74LS163A Synchronous
4-Bit Binary Counters
May 1992
Absolute Maximum Ratings (Note)
Note: The ‘‘Absolute Maximum Ratings’’ are those values
beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The
parametric values defined in the ‘‘Electrical Characteristics’’
table are not guaranteed at the absolute maximum ratings.
The ‘‘Recommended Operating Conditions’’ table will define
the conditions for actual device operation.
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.
Supply Voltage
7V
Input Voltage
7V
Operating Free Air Temperature Range
b 55§ C to a 125§ C
DM54LS and 54LS
DM74LS
0§ C to a 70§ C
Storage Temperature Range
b 65§ C to a 150§ C
Recommended Operating Conditions
Symbol
VCC
Supply Voltage
VIH
High Level Input Voltage
VIL
Low Level Input Voltage
IOH
High Level Output Current
IOL
Low Level Output Current
fCLK
Clock Frequency (Note 1)
tW
tSU
TA
Max
Min
Nom
Max
4.5
5
5.5
4.75
5
5.25
2
2
0.7
0.8
V
b 0.4
b 0.4
mA
4
0
25
20
0
0
20
6
20
6
Clear
20
9
20
9
Pulse Width
(Note 2)
Clock
25
25
Clear
25
25
Hold Time
(Note 1)
V
V
Clock
Setup Time
(Note 1)
Units
Nom
Pulse Width
(Note 1)
Hold Time
(Note 2)
tREL
DM74LS161A
Min
Clock Frequency (Note 2)
Setup Time
(Note 2)
tH
DM54LS161A
Parameter
0
Data
20
8
20
8
25
17
25
17
Load
25
15
25
15
Data
20
20
30
30
Load
30
30
mA
MHz
20
MHz
ns
ns
Enable P
Enable P
8
25
ns
ns
Data
0
b3
0
b3
Others
0
b3
0
b3
ns
Data
5
5
Others
5
5
Clear Release Time (Note 1)
20
20
ns
Clear Release Time (Note 2)
25
25
ns
Free Air Operating Temperature
b 55
125
Note 1: CL e 15 pF, RL e 2 kX, TA e 25§ C and VCC e 5.5V.
Note 2: CL e 50 pF, RL e 2 kX, TA e 25§ C and VCC e 5.5V.
2
0
ns
70
§C
’LS161 Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol
Parameter
Min
Typ
(Note 1)
DM54
2.5
3.4
DM74
2.7
3.4
Conditions
Max
Units
b 1.5
V
VI
Input Clamp Voltage
VCC e Min, II e b18 mA
VOH
High Level Output
Voltage
VCC e Min, IOH e Max
VIL e Max, VIH e Min
Low Level Output
Voltage
VCC e Min, IOL e Max
VIL e Max, VIH e Min
DM54
0.25
DM74
0.35
0.5
IOL e 4 mA, VCC e Min
DM74
0.25
0.4
VCC e Max
VI e 7V
Enable T
0.2
Clock
0.2
Load
0.2
Others
0.1
Enable T
40
VOL
II
IIH
Input Current @ Max
Input Voltage
High Level Input
Current
VCC e Max
VI e 2.7V
V
0.4
Clock
40
Load
40
Others
IIL
Low Level Input
Current
VCC e Max
VI e 0.4V
IOS
Short Circuit
Output Current
ICCH
Supply Current with
Outputs High
VCC e Max
(Note 3)
ICCL
Supply Current with
Outputs Low
VCC e Max
(Note 4)
(Note 2)
mA
mA
20
Enable T
b 0.8
Clock
b 0.8
Load
b 0.8
Others
VCC e Max
V
mA
b 0.4
DM54
b 20
b 100
DM74
b 20
b 100
18
31
19
32
mA
mA
mA
Note 1: All typicals are at VCC e 5V, TA e 25§ C.
Note 2: Not more than one output should be shorted at a time, and the duration should not exceed one second.
Note 3: ICCH is measured with the load high, then again with the load low, with all other inputs high and all outputs open.
Note 4: ICCL is measured with the clock input high, then again with the clock input low, with all other inputs low and all outputs open.
’LS161 Switching Characteristics
at VCC e 5V and TA e 25§ C (See Section 1 for Test Waveforms and Output Load)
Symbol
Parameter
From (Input)
To (Output)
RL e 2 kX
CL e 15 pF
Min
Max
25
CL e 50 pF
Min
Units
Max
fMAX
Maximum Clock Frequency
tPLH
Propagation Delay Time
Low to High Level Output
Clock to
Ripple Carry
25
30
ns
tPHL
Propagation Delay Time
High to Low Level Output
Clock to
Ripple Carry
30
38
ns
tPLH
Propagation Delay Time
Low to High Level Output
Clock to Any Q
(Load High)
22
27
ns
tPHL
Propagation Delay Time
High to Low Level Output
Clock to Any Q
(Load High)
27
38
ns
3
20
MHz
’LS161 Switching Characteristics
at VCC e 5V and TA e 25§ C (See Section 1 for Test Waveforms and Output Load) (Continued)
Symbol
RL e 2 kX
From (Input)
To (Output)
Parameter
CL e 15 pF
Min
CL e 50 pF
Max
Min
Units
Max
tPLH
Propagation Delay Time
Low to High Level Output
Clock to Any Q
(Load Low)
24
30
ns
tPHL
Propagation Delay Time
High to Low Level Output
Clock to Any Q
(Load Low)
27
38
ns
tPLH
Propagation Delay Time
Low to High Level Output
Enable T to
Ripple Carry
14
27
ns
tPHL
Propagation Delay Time
High to Low Level Output
Enable T to
Ripple Carry
15
27
ns
tPHL
Propagation Delay Time
High to Low Level Output
Clear to
Any Q
28
45
ns
Recommended Operating Conditions
Symbol
DM54LS163A
Parameter
VCC
Supply Voltage
VIH
High Level Input Voltage
VIL
Low Level Input Voltage
DM74LS163A
Nom
Max
Min
Nom
Max
4.5
5
5.5
4.75
5
5.25
2
2
V
b 0.4
mA
8
mA
25
MHz
20
MHz
High Level Output Current
IOL
Low Level Output Current
4
fCLK
Clock Frequency (Note 1)
tSU
TA
20
0
0
Pulse Width
(Note 1)
Clock
20
6
20
6
Clear
20
9
20
9
Pulse Width
(Note 2)
Clock
25
25
Clear
25
25
Setup Time
(Note 1)
Data
20
8
0
20
8
Enable P
25
17
25
17
Load
25
15
25
15
Data
20
20
30
30
Load
30
Data
0
b3
0
b3
Others
0
b3
0
b3
Data
5
5
Others
5
5
Clear Release Time (Note 1)
20
20
Clear Release Time (Note 2)
25
25
Hold Time
(Note 1)
Free Air Operating Temperature
ns
ns
Enable P
Hold Time
(Note 2)
tREL
25
Clock Frequency (Note 2)
Setup Time
(Note 2)
tH
V
0.8
IOH
0
V
0.7
b 0.4
tW
Units
Min
ns
ns
30
b 55
125
Note 1: CL e 15 pF, RL e 2 kX, TA e 25§ C and VCC e 5V.
Note 2: CL e 50 pF, RL e 2 kX, TA e 25§ C and VCC e 5V.
4
0
ns
ns
ns
ns
70
§C
’LS163 Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol
Parameter
Min
Typ
(Note 1)
DM54
2.5
3.4
DM74
2.7
3.4
Conditions
Max
Units
b 1.5
V
VI
Input Clamp Voltage
VCC e Min, II e b18 mA
VOH
High Level Output
Voltage
VCC e Min, IOH e Max
VIL e Max, VIH e Min
Low Level Output
Voltage
VCC e Min, IOL e Max
VIL e Max, VIH e Min
DM54
0.25
0.4
DM74
0.35
0.5
IOL e 4 mA, VCC e Min
DM74
0.25
0.4
VCC e Max
VI e 7V
Enable T
VOL
II
IIH
Input Current @ Max
Input Voltage
High Level Input
Current
VCC e Max
VI e 2.7V
V
0.2
Clock, Clear
0.2
Load
0.2
Others
0.1
Enable T
40
Load
40
Clock, Clear
40
Others
IIL
Low Level Input
Current
VCC e Max
VI e 0.4V
IOS
Short Circuit
Output Current
ICCH
Supply Current with
Outputs High
VCC e Max
(Note 3)
ICCL
Supply Current with
Outputs Low
VCC e Max
(Note 4)
(Note 2)
mA
mA
20
Enable T
b 0.8
Clock, Clear
b 0.8
Load
b 0.8
Others
VCC e Max
V
mA
b 0.4
DM54
b 20
b 100
DM74
b 20
b 100
18
31
18
32
mA
mA
mA
Note 1: All typicals are at VCC e 5V, TA e 25§ C.
Note 2: Not more than one output should be shorted at a time, and the duration should not exceed one second.
Note 3: ICCH is measured with the load high, then again with the load low, with all other inputs high and all outputs open.
Note 4: ICCL is measured with the clock input high, then again with the clock input low, with all other inputs low and all outputs open.
’LS163 Switching Characteristics
at VCC e 5V and TA e 25§ C (See Section 1 for Test Waveforms and Output Load)
Symbol
Parameter
From (Input)
To (Output)
RL e 2 kX
CL e 15 pF
Min
Max
25
CL e 50 pF
Min
Units
Max
fMAX
Maximum Clock Frequency
tPLH
Propagation Delay Time
Low to High Level Output
Clock to
Ripple Carry
25
30
ns
tPHL
Propagation Delay Time
High to Low Level Output
Clock to
Ripple Carry
30
38
ns
tPLH
Propagation Delay Time
Low to High Level Output
Clock to Any Q
(Load High)
22
27
ns
tPHL
Propagation Delay Time
High to Low Level Output
Clock to Any Q
(Load High)
27
38
ns
5
20
MHz
’LS163 Switching Characteristics
at VCC e 5V and TA e 25§ C (See Section 1 for Test Waveforms and Output Load) (Continued)
Symbol
Parameter
RL e 2 kX
From (Input)
To (Output)
CL e 15 pF
Min
Max
CL e 50 pF
Min
Units
Max
tPLH
Propagation Delay Time
Low to High Level Output
Clock to Any Q
(Load Low)
24
30
ns
tPHL
Propagation Delay Time
High to Low Level Output
Clock to Any Q
(Load Low)
27
38
ns
tPLH
Propagation Delay Time
Low to High Level Output
Enable T to
Ripple Carry
14
27
ns
tPHL
Propagation Delay Time
High to Low Level Output
Enable T to
Ripple Carry
15
27
ns
tPHL
Propagation Delay Time
High to Low Level Output
Clear to Any Q
(Note 1)
28
45
ns
Note 1: The propagation delay clear to output is measured from the clock input transition.
Logic Diagram
LS163A
TL/F/6397 – 2
The LS161A is similar, however, the clear buffer is connected directly to the flip flops.
6
Parameter Measurement Information
Switching Time Waveforms
TL/F/6397 – 3
Note A: The input pulses are supplied by generators having the following characteristics: PRR s 1 MHz, duty cycle s 50%, ZOUT & 50X, tr s 10 ns, tf s 10 ns.
Vary PRR to measure fMAX.
Note B: Outputs QD and carry are tested at tn a 16 where tn is the bit time when all outputs are low.
Note C: VREF e 1.5V.
Switching Time Waveforms
TL/F/6397 – 4
Note A: The input pulses are supplied by generators having the following characteristics: PRR s 1 MHz, duty cycle s 50%, ZOUT & 50X, tr s 6 ns, tf s 6 ns. Vary
PRR to measure fMAX.
Note B: Enable P and enable T setup times are measured at tn a 0.
Note C: VREF e 1.3V.
7
Timing Diagram
LS161A, LS163A Synchronous Binary Counters
Typical Clear, Preset, Count and Inhibit Sequences
TL/F/6397 – 5
Sequence:
(1) Clear outputs to zero
(2) Preset to binary twelve
(3) Count to thirteen, fourteen, fifteen, zero, one, and two
(4) Inhibit
8
9
Physical Dimensions inches (millimeters)
Ceramic Leadless Chip Carrier Package (E)
Order Numbers 54LS161ALMQB or 54LS163ALMQB
NS Package Number E20A
16-Lead Ceramic Dual-In-Line Package (J)
Order Numbers 54LS161ADMQB, 54LS163ADMQB, DM54LS161AJ or DM54LS163AJ
NS Package Number J16A
10
Physical Dimensions inches (millimeters) (Continued)
16-Lead Small Outline Molded Package (M)
Order Number DM74LS161AM or DM74LS163AM
NS Package Number M16A
16-Lead Molded Dual-In-Line Package (N)
Order Numbers DM74LS161AN, DM74LS163AN
NS Package Number N16E
11
54LS161A/DM54LS161A/DM74LS161A, 54LS163A/DM54LS163A/DM74LS163A Synchronous
4-Bit Binary Counters
Physical Dimensions inches (millimeters) (Continued)
16-Lead Ceramic Flat Package (W)
Order Numbers 54LS161AFMQB, 54LS163AFMQB,
DM54LS161AN or DM54LS163AW
NS Package Number W16A
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